Water Heater Basics

What you’ll find on this page: the keys to understanding how water heaters work, what makes them fail, what can be done to save them, the ups and downs of tankless, how to get your hands dirty (and maybe your feet wet), and how to choose a new heater if this knowledge comes too late for your current one, as well as safety and emergency preparedness issues.

Safety illustration showing parts of water heater

Until Larry and Suzanne Weingarten began experimenting, more than 30 years ago, not many people in the United States knew that water heaters could be economically serviced and made to last.

Somebody called the Weingartens to an apartment complex because the water heaters were making strange noises. All anybody knew to do then was replace them.

They learned what caused the noise — sediment — and how to easily stop it. They learned about the part that really controls the life of a water heater — the anode rod.

They invented a unique vacuum cleaner, the Muck-Vac, that cleans the tank while it’s full of water, and a special tool that makes it easier to remove anodes. Then they wrote a book, the Water Heater Workbook. Finally, they and an associate began teaching other people how to do this work.

Our goal is to save a good chunk of the 6.5 million water heaters that fail each year and wind up in the landfill. We hope yours is among the ones we save. We also want to influence you to make wise buying choices.

To us, preventive maintenance includes buying the right tank in the first place, setting it up in a unique way, and then maintaining it. It can also mean retrofitting the one you already have to do the same thing.

The following topics tell you, among other things, about the construction of a water heater and why it’s necessary to make some changes to permit maintenance, as well as describing what that entails and how to do it.

  • The Inside Story — Time to learn a little about the innards of a water heater. Then you’ll understand how construction affects maintenance and longevity.
  • Lingo — This is our glossary of water heater terms. It’s properly a part of the Troubleshooting section, but people reading these articles might also have need of it. So if you wonder what a term means, check it out, then come back to this page or the page you left to continue your studies.
  • What Kills Water Heaters — Here is a quick list of things to be concerned about. Rust is the most usual and obvious cause of water heater failure, but there are other causes, some of them subtle.
  • Anodes — A matter of life and death to your tank. Even though practically every water heater has one, scarcely anybody knows that they’re there — and that they can be replaced.
  • When Anodes Passivate — We finally decided this deserved a page of its own. Occasionally, sacrificial anodes do something strange. They sort of go to sleep. The why of it is unclear. But it’s good to recognize the symptoms, and also consider what to do about it.
  • Powered Anodes — While more costly than sacrificial anodes, they have a role to play where water softeners are being used and when people with softened water have smelly water.
  • Sediment — It lowers energy efficiency, helps harm the tank bottom, causes odd noises and burns out recirculation pumps and heating elements.
  • Water Pressure Issues — Most people would never think to check the water pressure, but what good is changing anodes and controlling sediment buildup if hidden high pressure or thermal expansion spikes are going to wreck the heater and plumbing anyway? Learn the simple test for these things and what to do if you find them.
  • Safety — Codes vary across the United States, but here are some of the basics.
  • Emergency Preparedness and Water Heaters — Your water heater could be the only drinkable water around in a disaster, but unless you heed some of our advice, you may be left high and dry.
  • Tankless Water Heaters — Instantaneous water heaters sound like a big improvement over tank-type heaters. But are they? Here’s the nitty-gritty. Also described here are some cool technologies for saving energy and water.
  • Plumbing Connectors — There are several ways to connect a water heater to its plumbing. Some are better than others.
  • Temperature/Pressure Relief Valves — Every water heater has one, but most people ignore them. To their peril.
  • Drain Valves — Every heater has one of these, too, but most never get used. If they ARE used, often they are troublesome.
  • Choosing a Water Heater — We won’t choose for you, but we can tell you how to make an informed choice.
  • Preventive Maintenance Tasks — Our water heater is now 39 years old because we’ve maintained it in the way we advocate here. See what we’ve done to our tank to keep it going that long.
  • Know-How — This is the hands-on guide to checking and possibly replacing your anode, dip tube and drain valve.
  • Insulation and Energy Efficiency — Comparing water heaters has gotten more complicated, but it can still be done, and should be done.
  • Water Heating According to Larry — Larry Weingarten, who pioneered most of the ideas, tools and techniques encompassed on this website, uses our forum, The Tank, to not merely answer people’s questions, but also to elaborate his ideas about how things should be. This page constitutes some of those questions and some of his answers.
  • Save Water, Save Energy — Three mechanical systems and two design systems aimed at cutting your wait for hot water, keeping too much cold water from being wasted while waiting for hot water to arrive at a fixture, and saving energy.
  • Life-Cycle Cost Analysis — A simple tool for comparing the overall cost of different water heaters you might be considering buying.
  • Tools for Maintenance — We tell you to use certain tools to do certain maintenance on water heaters. Here is a description of what those are and what they do.
  • What 2015 Changes Meant for Water Heaters — The Department of Energy issued new energy regulations in April 2015 that resulted in most water heaters getting taller or wider, and eliminated some types that people have used for years.
Water Heater Rescue

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